From: Vincent Lefevre <vincent@vinc17.net>
To: "Ævar Arnfjörð Bjarmason" <avarab@gmail.com>
Cc: git@vger.kernel.org
Subject: Re: git fails with a broken pipe when one quits the pager
Date: Mon, 1 Feb 2021 11:34:29 +0100 [thread overview]
Message-ID: <20210201103429.GT623063@zira.vinc17.org> (raw)
In-Reply-To: <87o8h4omqa.fsf@evledraar.gmail.com>
On 2021-01-31 21:49:49 +0100, Ævar Arnfjörð Bjarmason wrote:
> On Sun, Jan 31 2021, Vincent Lefevre wrote:
> > FYI, I already have the exit status already in my prompt (the above
> > commands were just for the example). Still, the git behavior is
> > disturbing.
> >
> > Moreover, this doesn't solve the issue when doing something like
> >
> > git log && some_other_command
>
> What issue? That we're returning an exit code per getting a SIGHUP here
> is a feature. Consider:
>
> git -c core.pager=/bin/false log && echo showed you the output
If the pager exists with a non-zero exit status, it is normal to
return a non-zero exit status. This was not the bug I reported.
> > No! I want to be warned about real SIGPIPEs.
>
> Not being able to write "git log" output is a real SIGPIPE.
Which is not the case here, because the full output has never been
requested by the user.
> Is it because in your mind it's got something to do with the "|" shell
> piping construct? The SIGPIPE is sent by the kernel, so it's no less
> expected in cases like:
>
> git log && echo foo
>
> Than:
>
> git log | cat
See the difference (without the patch) between
$ git log && echo foo; echo $?
141
and
$ git log | head; echo $?
[...]
0
[...]
> Maybe we have users who'd like to work around zsh's "setopt
> PRINT_EXIT_VALUE" mode (would you want this patch if you could make zsh
> ignore 141?).
zsh is working as expected, and as I've already said, I ***WANT***
SIGPIPE to be reported by the shell, as it may indicate a real failure
in a script. BTW, I even have a script using git that relies on that:
{ git rev-list --author "$@[-1]" HEAD &&
git rev-list --grep "$@[-1]" HEAD } | \
git "${@[1,-2]:-lv}" --no-walk --stdin
return $((pipestatus[2] ? pipestatus[2] : pipestatus[1]))
Here it is important not to lose any information. No pager is
involved, the full output is needed. If for some reason, the
LHS of the pipe fails due to a SIGPIPE but the right hand side
succeeds, the error will be reported.
The fact is that with a pager, the SIGPIPE with a pager is normal.
Thus with a pager, git is reporting a spurious SIGPIPE, and this
is disturbing.
--
Vincent Lefèvre <vincent@vinc17.net> - Web: <https://www.vinc17.net/>
100% accessible validated (X)HTML - Blog: <https://www.vinc17.net/blog/>
Work: CR INRIA - computer arithmetic / AriC project (LIP, ENS-Lyon)
next prev parent reply other threads:[~2021-02-01 10:35 UTC|newest]
Thread overview: 60+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-15 16:15 git fails with a broken pipe when one quits the pager Vincent Lefevre
2021-01-29 23:48 ` [PATCH] pager: exit without error on SIGPIPE Denton Liu
2021-01-30 8:29 ` Johannes Sixt
2021-01-30 12:52 ` Johannes Sixt
2021-02-01 15:03 ` Ævar Arnfjörð Bjarmason
2021-02-01 17:47 ` Junio C Hamano
2021-02-01 19:52 ` Ævar Arnfjörð Bjarmason
2021-02-01 20:55 ` Junio C Hamano
2021-02-02 2:05 ` Ævar Arnfjörð Bjarmason
2021-02-02 4:45 ` Junio C Hamano
2021-02-02 5:25 ` Junio C Hamano
2021-02-02 7:45 ` Johannes Sixt
2021-02-02 20:13 ` Junio C Hamano
2021-02-02 22:15 ` Johannes Sixt
2021-02-02 22:21 ` Junio C Hamano
2021-02-03 17:07 ` Johannes Sixt
2021-02-03 18:12 ` Junio C Hamano
2021-02-04 15:10 ` Vincent Lefevre
2021-02-03 2:45 ` Ævar Arnfjörð Bjarmason
2021-02-03 2:54 ` Junio C Hamano
2021-02-03 3:36 ` Ævar Arnfjörð Bjarmason
2021-02-03 17:19 ` Johannes Sixt
2021-01-31 1:47 ` git fails with a broken pipe when one quits the pager Ævar Arnfjörð Bjarmason
2021-01-31 3:36 ` Vincent Lefevre
2021-01-31 3:47 ` Vincent Lefevre
2021-01-31 20:49 ` Ævar Arnfjörð Bjarmason
2021-02-01 10:34 ` Vincent Lefevre [this message]
2021-02-01 11:33 ` Chris Torek
2021-02-01 12:36 ` Vincent Lefevre
2021-02-01 12:53 ` Chris Torek
2021-02-01 15:17 ` Vincent Lefevre
2021-02-01 15:00 ` Ævar Arnfjörð Bjarmason
2021-02-01 12:10 ` Ævar Arnfjörð Bjarmason
2021-02-01 14:48 ` Vincent Lefevre
2021-02-01 15:44 ` Ævar Arnfjörð Bjarmason
2021-02-01 22:16 ` Johannes Sixt
2021-02-03 2:48 ` Ævar Arnfjörð Bjarmason
2021-02-03 17:11 ` Johannes Sixt
2021-02-03 15:26 ` Vincent Lefevre
2021-02-04 0:14 ` Ævar Arnfjörð Bjarmason
2021-02-04 15:38 ` Vincent Lefevre
2021-02-01 14:49 ` [PATCH 0/3] pager: test for exit behavior & trace2 bug fix Ævar Arnfjörð Bjarmason
2021-02-02 1:59 ` [PATCH v2 0/5] " Ævar Arnfjörð Bjarmason
2021-02-02 1:59 ` [PATCH v2 1/5] pager: refactor wait_for_pager() function Ævar Arnfjörð Bjarmason
2021-02-02 1:59 ` [PATCH v2 2/5] pager: test for exit code with and without SIGPIPE Ævar Arnfjörð Bjarmason
2021-02-02 8:50 ` Denton Liu
2021-02-05 7:47 ` Johannes Sixt
2021-02-02 1:59 ` [PATCH v2 3/5] run-command: add braces for "if" block in wait_or_whine() Ævar Arnfjörð Bjarmason
2021-02-02 2:00 ` [PATCH v2 4/5] pager: properly log pager exit code when signalled Ævar Arnfjörð Bjarmason
2021-02-05 7:58 ` Johannes Sixt
2021-02-05 11:37 ` Junio C Hamano
2021-02-02 2:00 ` [WIP/PATCH v2 5/5] WIP pager: respect exit code of pager over SIGPIPE Ævar Arnfjörð Bjarmason
2021-02-01 14:49 ` [PATCH 1/3] pager: test for exit code Ævar Arnfjörð Bjarmason
2021-02-01 14:49 ` [PATCH 2/3] pager: refactor wait_for_pager() function Ævar Arnfjörð Bjarmason
2021-02-01 14:49 ` [PATCH 3/3] pager: properly log pager exit code when signalled Ævar Arnfjörð Bjarmason
2021-02-01 18:07 ` Junio C Hamano
2021-02-01 19:21 ` Ævar Arnfjörð Bjarmason
2021-02-01 18:15 ` Junio C Hamano
2021-02-01 19:23 ` Ævar Arnfjörð Bjarmason
2021-02-01 22:04 ` git fails with a broken pipe when one quits the pager Johannes Sixt
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